I have had my 2012 unlimited Saharah for about one month now. It's automatic transmission, no modifications. On several occasions I am driving, the check engine light turns on and it won't accelerate past 40 mph. The check engine light will turn off on its own within a couple of days. On one occasion I got it up to 60 mph then it lost all power. I have taken it to two different jeep dealers and they apparently cannot find anything wrong with it. when the engine light was still on, I took it to AutoZone and got the code. I took it to the dealer and they said it was an oil filter code. They say it has no stored codes and they cannot replicate the issue. Has anyone heard of this? Please help, what could this be???